Butterfly valve seat



D. G. FAWKES BUTTERFLY VALVE SEAT Feb. 2, 1960 2,923,524

Filed 00's. 24. 1956 2 Sheets-Sheet 1 F1151Y ff Feb. 2, 1960 D. G.FAwKl-:s

BUTTERFLY VALVE SEAT 2 Sheets-Sheet 2 Filed Oct. 24, 1956 United StatesPatent O BUTTERFLY VALVE SEAT Donald G. Fawkes, Chicago, lll., assignorto Henry Pratt Company, a corporation of Illinois Application October24, 1956, Serial YNo. 618,004`

9 Claims. (Cl. 251-306) This invention relates to a valve of the typeadapted The liner is best illustrated in Figures 1 and 2.V It isordinarily preferred to form the liner in a molding operation so thatitis an integral piecerof rubber having laterally enlarged hub sectionsl joined by arcuate portions 11, of generally uniform cross-sectionbetween the hubsections. 'In Figure 2, it will be noted that the ring ofthe liner has an inner surface 12 continuous around the -linerexcept-for the diametrically opposite openings exposed surface 12.

to open and close in the manner of a butterfly valve and moreparticularly to a seat liner for such a valve.

Buttery valves and valves having similar motion often close a gate bodyor disc against a rubber or rubber-hke seat liner carried in the valvehousing. Such liners are 13 made for the purpose of receiving the valveshaft. The valvedisc would ordinarily seat against the inner Immediatelyadjoining the surface 12 is a slightly outwardly sloping surface'14 onone side and 15 on the other lside. These surfaces provide a means forguiding the disc of the valve onto the surface 12. Y

The outer side of the liner is generally U-shaped in section and may beformed with a central groove 16, Y

dove-tailed in section. This groove could be square as well asdove-tailed although the latter is preferred. Ordinarily, the outeredgesl7 and 1S are upright surfaces l parallel to each other for thepurposerof fitting tightly within the valve casing against retainermembers formed as shown in Figure 3. Each'retainer member 20 is an`arcuate segment of metal, hard rubber or reinforced rubber adapted tolay beside the liner against either a surface l17 or surface 18 withitsends 21 tightly abutting a shoul- Another object is to provide avalve seat liner with av particular structure enabling a seal underpressure between the valve disc and the valve housing to prevent leakagepast the seat.

Another object is to provide a valve liner of a new and improvedstructure requiring no reinforcing.

A further object is to provide a new valve` seat structure which may beused in relatively small to very large valves operating from vacuum tosuperatmospheric pressures thus permitting standardization of the valveseat structure throughout an extensive line of valves.

Further objectives, features and advantages of the present inventionwill be apparent from the following description of a preferredembodiment illustrated in the accompanying drawings, in which:

Figure 1 is a side plan view of the valve liner of this invention,

Figure 2 is a sectional view taken substantially through the center ofsymmetry of the liner shown in Figure 1,

Figure 3 is a side elevational view of one of the retainers used to holdthe seat in place in a valve casing,

Figure 4A is a fragmentary sectional View through an exemplary valvehousing or casing adapted to receive the liner of Figures 1 and 2,

Figure 5 is an enlarged fragmentary sectional view through a portion ofthe housing taken at the valve shaft opening,

Figure 6 is a view similar to Figure 5 taken substantially along line 66 in Figure 5, and

Figure 7 is a fragmentary sectional view taken substantially along line7-7 in Figure 4, showing a valve disc in position against the seatliner.

The embodiment of the present invention is illustrated as employed in abutterfly valve having a bolt flange for connection to a flanged pipe.The liner itself is formed of rubber material so that a valve discmounted upon a shaft may be turned to rest against the medial portion ofthe liner. The liner structure is applicable to many types and sizes ofbutterfly valves and the principles involved may be used in severaltypes of valves wherein a closure body may be shifted into and out ofcontact with a valve seat liner.

Vlitted in place to receive the valve shaft.

der 22 formedon the laterally enlarged hub sections of the liner. Insome instances, more than four retainers may be used, in which case someof the retainers will abut each other end to end. Y

Each valve casing orV housing intended to receive the liner of Figures land 2 may be formed with an annular internal groove or recess generallyindicated 25 in Figure 4. The groove is machined into the housing so asto have outer surfaces 26 and 27 generally normal to a center linethrough the valve housing. An upstanding rib 28 is formed medially ofthe groove 25 in order to ex-VV tend into the-medial groove 16 formed inthe valve liner. Retainers 20 lill the space between the outer surfaces26 and 27 of thehousing groove and the side faces 17 and 18 of the valveliner and tightly abut the shoulders on the enlargements. Four retainersor more thus normally lock the liner inplace in the valve housing. Atthe same time,` the retainers may be physically pulledrout of pos itionin order to permit replacement ofk a worn liner.

The valve casing shown in Figure 4 has flanges 30 at eitherside equippedwith bolt holes 31, although other types of valve casings may be equallywell-suited for use with the present invention. It should be noted thatthe valve casing illustrated has a length between its llanges'alVgreatly in excess of the width of the liner receiving groove 25. Thesection of the casing illustrated generally as 40 in Figure 4 was takenthrough the shaft openings 32 and 33 wherein sleeve bearings 34 and 35are press As illustrated inl Figures 5 and 6, the opening 13 in theliner matches up in alignment with the opening 36 formed by the bearing34.

One of the advantages of the present form of valve liner is its abilityto seal against the leakage from oneside to the other. each enlargedportion 10 of the liner has an inner flat surface 37 which may be sealedwith pressure against Athe hub of the valve disc immediately around thevalve shaft.' In the placement of the disc in the valve housing, therubber material of the liner will be slightly compressed to form a shaftseal around the shaft opening 13. The valve disc is fragmentarilyshown'at 38 in Figure 7 as compressing the thin central section 39 ofthe'valve liner v material. As the disc sweeps onto the surface'lZ, il:V

compresses the rubber material of the liner so as to form Y' a sealbetween itself and the Vliner material as well as to patented Feb. 2,1960 i A valve disc to prevent Y It will be noted that' the valvehousing beyond the static seal.

V $2,923,524 1 j p compress the material against the central rib 28 inthe valve housing. ln this manner a pressure seal is formed v betweenthe rubber liner and the metal parts on either side of the thin centralsection. Ordinarily, no leakage will occur past this seal.

.A further advantage, ofthe present -liner structureis that it may bemade quite narrow so that reinforcing in the rubber is not needed. Oneof 4the problems ofemploying rubber valve liners has been that `fluidunder pressure will get behind the linerwand -cause -it to;bulgeinwardly around a closed valve disc. Under'Vthese circumstances, thedisc may not be opened, thus causing a failure in valve operation. Inthe present structureanyiiuid under pressure that does findV its wayback `of the valve liner mustiirst pass the thin section of theseatwhere it is squeezed against the valve `housing rib 28 forming astatic sealagainst such tiuid passage. Should any fluid get past thestatic seal so formed, such fluid v-will pass harmlessly to the lowpressure side of the Valve since there is no clamp or otherstructurerholding the liner to The seat material ispressed against therib 28 Vbut otherwise is held only frictionally in place. Thus, noymetal, canvas or other reinforcementV is required in the liner `inorderto avoid the problem previously encountered.

The present liner str upon the formeof the valve housing. Thelinermraybe` employed in valves from 4 inches-in diameter `up to 7 feetin diameter without materially changing the Vstructure. ln valves of thewafer type having no anges in. itself, the valve liner may be placed insuch a position that it is not contacted by the adjoining pipe anges andthus not, subject to damage upon insertion or removal of the valve. Y IY The present valve liner provides va simple solution to a problem ofretaining rubber or rubberlikevalve seats in valves of various kinds andsizes. It permits standardization throughout a line of valves which mayrange in operational requirements of vacuum to as lhighas 250 lbs. persquare inch with the valve closed.

TheV foregoing detailed description has been givenrfor clearn'ess ofunderstanding only, and no unnecessary limitations should be understoodtherefrom, for some modiiications will be obvious to those skilled inthe art.V

I claim:

l`. In a butteriiy valve having a housing and a 'valve disc, a seat forthe disc comprising: a onefpiece annular ringof resilient materialhaving a pair of diametrically opposite laterally enlarged and centrallyapertured portions and an otherwise generally uniform section, saidhousing havinga disc supporting shaft for projection through theapertured portions and an annular groove at leastiequal in width to saidenlarged portions for receiving the annular seat, said groove beingformed Within the valve casing and being lof lesser width than the widthof the casing, and arcuate retainer members frictionally engaging thecasing and the annular ring while'abutting opposite enlarge-d portionsendwise to retain the -seat in the valve housing groove.

2.'In`a butterfly valve structure including a housing and a disc, a seatstructure, comprising: a resilient seat ring having a generally uniformcross-section extending between diametrically opposite laterallyenlarged shaft receiving portions, and an inner exposed Vsurface tosealagainst theV disc in closed position, said housing having a recessedannular groove entirely within thevalve casing and generally equal inwidth to that of said seat ring enlarged `portions for receiving theseat ring; seat ring re# tainers frictionally binding the ring in thehousing groove,

said retainers being removably inserted in the groove beside the ringand extending between and abutting said enlarged portions endwise tosecure the ring in'place.

3. A seat structure for a valve as specified in claim 2 wherein ;theseat ring has a relatively thin central section extendingcircumferentially and the housing groove is shaped to receive the seatring in intimate contacttherewith.`

V4. A seat structure for a valve as specified in claim 2 wherein ,thehousing has an inwardly projecting tongue Vcentrally of said recessedgroove and the seat ring is shaped to embrace the tongue with saidretainers frictionally holding each circumferential side of the seatring against the tongue. A

5. A seat 'structure for `a valve as specified in claim 4 wherein-thetongue Visdoveftailed in sectional shape.

6. A seat structurefor a valve including` a housing and Y a rotatableclosure on `a shaft, comprising: a resilient ucture is independent inVits form annular ring having an inner 'surface to be contacted by i theclosure for sealing and.. 0Pl10ite.enlarged portions apertured toreceive the shaft, said housing having an internal annular groove of`uniform cross-section receiv-` ing the ring with the enlarged portionssnug in the groove, and retainer segments `bearing endwise against theenlarged portionsand laterallyagainst the housing .andring to retain`the `ring in place in the housing groove with the valve closure uponthe shaft bearing outwardly against the'ring enlarged portions about theshaft. i

7. A valve seat for a 4butt'ery valve having a casing carrying avalveidisc, comprising:r an annulus of resilient material extending,around the interior of the casing, said ,annulus having aninner-exposed surface to seal against the valveidisc in closed `positionand anyouter surface including a medial groove providing the vannuluswith a relatively thin section'opposite the disc in closed position,said casing having-a recess therein to receive said annulus and having arib in `the recessextending into said medial groove'permitting saidrelatively `thinsection of'resilient` material `centrally of the annulusto `be compressed `between -the casing and disc in closedposition; andarcuate keeper members extending along each side of the annulus, saidannulus and keeper members extendingin tandem across the entire width ofsaid recess and frictionally retaining `the annuluspin the casing duringopening and y closingV of the valve.

8. A valve seat as specified in claim 7 wherein the groove intheannulusis dove-tailed in cross-section and said rib is formed `ofcorresponding shape filling said groove, so that the `disc may compressthe annulus material against the rib in closed position.

9. A valve seat for a butteriiy valve havinga casing carrying a valvedisc, comprising: an annulus of resilient material extending around theinterior of the-casing, said annulus having an inner exposed surface `toseal against the valve disc in closed position and a generally U-shapedcross-section providing a relatively thin medial `portion to becompressed between the `casing and disc, laterally enlargedportionsintegral with the annulus atdiametrical i positions thereon forreceivinga valve disc supporting shaft therethrough and sealing aboutsaid shaft supports `for the disc, said casing havingan annular groovetherein of a Width to receive the enlarged portions, said casing groovereceivingV said annulus and having a medial rib extending into the`U.shaped section, said enlargements being frictionally secured in thecasing groove and keeper i members extending between the enlargementsbeside the annulus frictionally engaging the annulus on one side `andthe valve casing on the opposite side to frictionally bind .the annulusin place in thecasing groove.

References Cited in the tile of this patent UNITED STATES PATENTS679,327 Germany of

